New prediction tool warns ships of blue whale hotspots

The largest animal on the planet, the endangered blue whale, often shares its habitat with busy shipping lanes. In the Pacific Ocean, they feed on krill in the California Current, which often overlaps with shipping lanes between San Francisco and Los Angeles. This leads to a number of ship and whale collisions every year that harm the population of gentle giants.

To prevent these ship strikes, NOAA Fisheries, alone with researchers from Oregon State University and the University of Maryland, has created a new tool that can predict where blue whales are likely to be congregating so that ships can avoid the "hotspots" and both ship and whale can continue their journey safely.

This tool uses over a decade's worth of data from Argos satellite tags that track blue whales on the West Coast as well as satellite observations of ocean conditions to make its predictions. The system called WhaleWatch looks at historical data from the tags to see where the whales tend to feed during certain times of the year as well as patterns in their behavior based on ocean conditions. With that, the system produces monthly hotspot maps of where ships face an increased risk of encountering blue whales.

“This is the first time that we’ve been able to predict whale densities on a year-round basis in near-real time,” said Helen Bailey, the WhaleWatch project leader at the University of Maryland Center for Environmental Science. “We hope it’s going to protect the whales by helping inform the shipping industry.”

The project publicly posts these maps on the NOAA Fisheries West Coast Region website every month. Armed with this information, shipping companies can revise their routes to avoid hotspots.

"No ship captain or shipping company wants to strike a whale," said Marine Exchange of Southern California Executive Director Kip Louttit. "If we can provide good scientific information about the areas that should be avoided, areas the whales are using, I think the industry is going to take that very seriously and put it to use."

Studies show that West Coast ships strike an average of two blue whales a year, but NOAA says the number is probably higher because some strikes may go unnoticed. The maps could help to eliminate ship strikes and could potentially protect whales from net and crab trap entanglements if they were used by the fishing industry as well.